1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus, each of which is provided with a piezoelectric element including a piezoelectric body layer made of a piezoelectric material and electrodes and is configured to eject liquid droplets from nozzle openings, and to the piezoelectric element.
2. Related Art
Representative examples of a liquid ejecting head include an ink jet recording head in which a part of a pressure generation chamber communicating with nozzles for ejecting ink droplets is configured of a vibrating plate and ink in the pressure generation chamber is pressurized by causing a piezoelectric element to deform the vibrating plate and is ejected as ink droplets from the nozzles. Examples of a piezoelectric element used in an ink jet recording head include a piezoelectric element configured by interposing a piezoelectric body layer made of a piezoelectric material with an electromechanical conversion function, for example, a crystallized dielectric material between two electrodes.
The piezoelectric material used in such a piezoelectric body layer is required to have an excellent piezoelectric property. In a case of a piezoelectric body layer with a crystal property of a rhombohedral system, it is desirable that the piezoelectric body layer is oriented in a (100) face in order for the piezoelectric body layer to sufficiently exhibit the piezoelectric property thereof. For example, a manufacturing method of a piezoelectric element is disclosed in which a piezoelectric body layer made of lead zirconate titanate (PZT) is formed above a lower electrode via a lead titanate layer in order to orient the lead zirconate titanate in the (100) face (see JP-A-2011-238774, for example). In addition, a technique is disclosed in which lanthanum nickel oxide (LNO) is used as a seed layer and bismuth ferrate-based and bismuth titanate-based piezoelectric body layers are preferentially oriented in the (100) face (see JP-A-2012-006182, for example).
However, a degree of orientation of the piezoelectric body layer in the vicinity of an end portion of the lower electrode is lower than that in the vicinity of the center thereof, for example, even in the piezoelectric body layer which is preferentially oriented in the (100) face, and fluctuation locally occurs in the orientation. Such fluctuation in orientation brings about degradation of the piezoelectric property.
In contrast, the piezoelectric body layer containing lead zirconate titanate or bismuth ferrate has a problem in that lead or bismuth in the piezoelectric body layer is diffused to the lower electrode and an adhesion layer provided between the vibrating plate and the lower electrode easily peels off. If such local fluctuation in orientation and peeling-off of the adhesion layer can be solved, it is possible to further enhance the piezoelectric property.
In addition, not only an actuator device which is mounted on a liquid ejecting head such as an ink jet recording head but also an actuator device which is mounted on another apparatus also has such a problem.